I. Description of the Prior Art
The present invention relates generally to a continuously variable traction roller transmission, and more particularly, to a power train supporting structure thereof.
II. Field of the Invention
One of previously known power train supporting structures of a continuously variable traction roller transmission is disclosed, for example, in JP-A 2-163553. This prior art transmission includes generally two pairs of traction roller transmission units on a torque transmission shaft and a forward/reverse change-over device disposed in tandem to the traction roller transmission unit on the front side or engine side thereof, and is provided with a wall between the traction roller transmission units and the forward/reverse change-over device for separating and supporting the two.
When carrying out power transmission between input and output disks of each traction roller transmission unit through power rollers, this prior art transmission can steplessly change the speed ratio by varying the inclination angle of the power rollers.
With the known power train supporting structures of a continuously variable traction roller transmission as disclosed in JP-A 2-163553, however, since the torque transmission shaft on which generally the two pairs of traction roller transmission units are disposed has a great length, and a loading cam device is disposed at the front end thereof, the loading cam device and the input disk of one of the traction roller transmission units are adjacent to the wall for separating a space for the traction roller transmission units and a space for the forward/reverse change-over device. Accordingly, if the loading cam device, bearing thereof, input disk, etc. are subassembled on the torque transmission shaft, the restriction on a working space makes mounting very difficult. Practically, almost all parts of the traction roller transmission units to be mounted on the torque transmission shaft are located inside the transmission, necessitating ensuring the working space inside the transmission, resulting in an enlarged size thereof.